\documentclass[11pt]{amsart}

\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{tikz}
\usepackage{pgfplots}
\usepackage{xcolor}

\usetikzlibrary{
  arrows,
  calc,
  decorations.markings,
  decorations.pathreplacing,
  dsp,
  fit,
  positioning
}
\input{../util/airfoils.tex}
\input{../util/wing.tex}
\input{../util/coordinate_systems.tex}
\input{../util/control.tex}

\begin{document}

\begin{figure}[h]
  \begin{center}
    \begin{tikzpicture}
      \begin{scope}[scale=0.3]
        % Wing.
        \draw[thick] ({-25.66 / 2}, -1.7) -- ({25.66 / 2}, -1.7);
        \draw[thick] ({-25.66 / 2}, 1.7) -- ({25.66 / 2}, 1.7);

        % Rotors.
        \draw[gray!75] ({-1.5 - 6},  1.7) circle (1.4);
        \draw[gray!75] ({-1.5 - 3},  1.7) circle (1.4);
        \draw[gray!75] ({-1.5 - 0},  1.7) circle (1.4);
        \draw[gray!75] ({ 1.5 + 0},  1.7) circle (1.4);
        \draw[gray!75] ({ 1.5 + 3},  1.7) circle (1.4);
        \draw[gray!75] ({ 1.5 + 6},  1.7) circle (1.4);
        \draw[gray!75] ({-1.5 - 6}, -1.7) circle (1.4);
        \draw[gray!75] ({-1.5 - 3}, -1.7) circle (1.4);
        \draw[gray!75] ({-1.5 - 0}, -1.7) circle (1.4);
        \draw[gray!75] ({ 1.5 + 0}, -1.7) circle (1.4);
        \draw[gray!75] ({ 1.5 + 3}, -1.7) circle (1.4);
        \draw[gray!75] ({ 1.5 + 6}, -1.7) circle (1.4);

        % Pylons.
        \draw[thick] (-4.5, -1.7) -- (-4.5, 1.7);
        \draw[thick] ( 4.5, -1.7) -- ( 4.5, 1.7);

        % Bridles.
        \draw[blue] (-4.5, 1.7) -- (0, -1.9);
        \draw[blue] ( 4.5, 1.7) -- (0, -1.9);

        % Tether.
        \draw[blue] (0, -1.9) -- (5, -10);

        % Cross-bracing.
        \draw[gray!50] (-4.5, -1.7) -- (4.5,  1.7);
        \draw[gray!50] (-4.5,  1.7) -- (4.5, -1.7);
      \end{scope}
    \end{tikzpicture}
  \end{center}
\end{figure}


\end{document}
